The correct answer is option B
A motor neuron is a neuron which consists of a cell body and axon. Cell body lies in the motor cortex, spinal cord or brainstem and axon projects outside the spinal cord or inside the spinal cord which directly or indirectly controls the function of muscles or glands.
The functions associated with the movement of muscles or glands are directly affected by the injured motor neurons.
The first species that colonizes new of undistributed land is called as pioneer species, or simply pioneers. If you check the meaning of pioneer, it's a type of person or entity that became the first to explore or exploit a certain something. In this case, they were the first species who explores the lands to create a society.
I believe the answer is (B) Parasitic.
<span>a. Fish have a single central heart; earthworms have several hearts.
</span>
Multi cellular organisms are made up of billions of cells each specialized to a unique role and these cells are organized into structural and functional units such as tissues and organs.
For each cell and organ to function optimally, it requires oxygen and nutrients and needs carbon dioxide and metabolic waste taken away in a continuous, never ending process.
<span>A mechanism is needed to accomplish the important function of transporting the relevant materials to and from the cell. The circulatory system fits this bill splendidly. It is a specialized organ system which allows blood and lymph to flow through the entire body carrying nutrients such as glucose, amino acids and electrolytes as well as oxygen to each cell, at the same time carting away carbon dioxide and all sorts of metabolic waste over to excretory organs to be expelled from the body.
</span>
<span>A soil horizon is a layer parallel to the soil surface</span><span>, whose physical characteristics differ from the layers above and beneath</span>